Arc welding



July 7, 1936- H. BREDTSCHN/EIDER ARC WELDING Filed Sept. 28, 19:54

Inventor Hans, Bredtschneioler,

' Hi Attorney,

Patented July 7, 1936- PATENT OFFlCE ARC WELDING Hans Bredtschneider,

Kassel, Germany, assignor to General Electric Company, a corporation ofNew York Application September 28, 1934, Serial No. 745,984

- In Germany October 10, 1933 3 Claims.

My invention relates to arc welding.

Due to the extremely high temperature of a welding arc, the light givenout by the arc is intensely brilliant. Furthermore it contains a largeproportion of ultra-violet radiation. This type of radiation ischemically active and will cause painful, although not necessarilypermanent, injury to human eyes and skin. It is customary,

therefore, for an arc welding operator to protect his head with a helmetor face shield which is provided with a window of protective glassthrough which he views the welding operation. The protective glassesemployed in such face shields and helmets, in order to cut down the Iamount of light transmitted. to the eyes of the operator during welding,are so opaque that it is impossible for the welder to view the work uponwhich he is performing a welding operation when the arc is extinguished.Heretofore, before initiatinga welding operation, the operator hasdisplaced his shield or raised his helmet in order to arrange the workparts and to place his electrode in proximityto the point at which hedesires to initiate the weldingoperation. He then replaced the helmet orface shield over his face, struck the arc and proceeded to weld. Such aprocedure resulted quite frequently in imperfect welds resulting fromfalse starts. Furthermore, since the operator found it necessary touncover his eyes at the beginning of the welding operation, itfrequently happened that. his eyes were exposed to the action of the arcfor brief periods of time, which caused painful physical injuries to theeye, for example, conjunctivitis.

It is an object of my invention to provide welding apparatus by means ofwhich the above disadvantages are eliminated.

In accordance with my invention the work is illuminated at the point ofwelding at an intensity approximately equal to that produced by thewelding arc during welding by an independent light source which ispreferably mounted on the electrode holder used by the operator inper-.

, forming his'welding .operation. I have also provided, in accordancewith my invention, means responsive to the ignition of the welding arc,for rendering this auxiliary illuminating means ineffective andresponsive to the extinction of the welding are for rendering this.illuminating means effective.

My invention will be better understood from a consideration of theembodiments illustrated in the attached drawing, Fig. 1 of which showsone embodimentoi my invention in which the il- In the arrangementillustrated in Fig. 1,. the 5 welding electrode i0 is supportedin aholder II to which welding current is supplied through a cable I2. Meansl3 are supported on the electrode holder for illuminating 'the work 14at the point of welding It. The construction of the illuminating meansis such that the work at the point of welding is illuminated atapproximately the same intensity as it is during welding when thewelding arc is ignited. This ,illuminating means may comprise anincandescent lamp or an 15 are lamp and suitable reflectors or lensesfor directing the light on to the work. In the arrangement illustrated,the illuminating means is an electric light source receiving its supplyof energy through the cable I2. In the arrangement illustrated, theconnection of the light source to its source of supply is under thecontrol of the welder who, by operating a switch I6 located in thehandle of the electrode'holder ii, may ignite or extinguish it at will.

In the arrangement illustratedin Fig. 2, the illuminating means isautomatically controlled and is energized aslong as the weldingelectrode is not in arcing engagement with the work. The. electrode Hithere illustrated is supported in an electrode holder H as in Fig. 1.One terminal ll of the welding generator. IB is connected to the work l9and the other terminal of the generator I8 is connected through aconductor 20 to the electrode clamp of the holder H. The electric lightsource 2! supplied on the holder II is con 7 nected through conductors22 and 23 to the weldinggenerator 98. It may be connected to anysuitable source, however. Inthe arrangement 11- lustrated, the generator18 is a constant potential machine and-the desired welding characteristics are obtained by means of a series resistance 24 inserted in thewelding circuit. Connected across this resistor 24 is a relay 25 whosecon-- tacts 26 are biased to the closed position by a spring 27! whenits operating coil is not energized by reason of the flow of currentthrough the welding circuit ll, 20. The relay 25 may be placed directlyin the welding circuit but I pre-. for to place it in shunt with theresistance 24 in that circuit.-

The system of Fig. 2 operates as follows:

When the electrode i0 is in arcing engagement with the work 89. asillustrated, the relay 25 is suiiiciently energized to separate itscontacts 26 and thereby interrupt the flow of electric 23. As soon asthe welding ore is extinguished, however; the relay 25 is deenergizedand itscontacts '26 are closed under the action oi spring 2?, therebycompleting the energizing circuit of the light source it which ispreferably of such a characteristic as to illuminate the work at thepoint of welding at an intensity approximately equal to that produced bythe welding'erc. By em ploying alight source of such intensity, the operator need not remove his helmet or loco shield to view the work uponwhich he is performing or welding operation when for any reeson'the welding are is extinguished. Thus, no te is lost during welding by theoperator removing and replacing his welding helmet or fnce shield, and

. furthermore, the eyes of the welding operator ere at no time exposedto the injurious effects of the light-Toys oi the welding ere. Elieillumination means employed be suitebly shielded so that the eyes of theoperator ere not exposed to the direct rays emanating therefrom and inthis way, when welding in derlzpieces such as bunkers (Rig. 1), boilerson'd the like, the opemtor can with safety remove his helmet or faceshield when no welding operation is being performed to view the worl';parts prior to initiating his welding operation or for supplying a newelectrode to his holder, although this letter operation moy, due to thelight source, be performed without re moving his helmet or face shield.

The illuminating meons above referred to may be of any suitable type,and is not necessorily on electrical moons such es speoii-lcollydescribed. Furthermore, the control for igniting and extinguishing theilluminating means y be oi any character so lone: as it functions toignite the illuminating means as long as the welding elec= trode is notin arcing engagement with the work. Thus for example, instead of thecurrent responsive means illustrated in Fig. 2, e voltage responsivemeans may be employed. Thlsvoltage iresponsive means could, for example,be connected across thecgwelding are and function to ignite theilluminating means when the welding ore is not ourrent to the lightsource 20 through conductors 22,

nosoooo ignited and to extinguish the illuminating means as soon as thewelding am, has been established. The equivalency of such voltage andcurrent controls are well known and further illustration or descriptionis considered unnecessary.

Many changes may be made in the embodiment illustrated and describedwithout departing from the spirit and scope of my invention. Thus,although I have shown and described two embodiments of my invention, itis to be understood that the sameis susceptible to various changes and Ireserve the right to employ such changes as may come within the scope ofthe claims hereto ennexed.

Wheat ll claim as new and desire to secure'loy Letters Patentofthe'United States is:

1. Apparatus enabling on arc welding operator to work without removinghis eye shield to view the wort: when the welding arc is extinguished,sold apparatus comprising; means for illuminating the work out the pointof welding et en intensity approximately equal to that produced by theweld log. etc during welding, and means accessible to the operator atthe point of welding for con-- trolling sold illuminating means.

2. An electrode holder for use in arc welding operations comprising anelectrode olamp,.means for supplying welding current to on electrodesupported in said cloimp, means mounted on said holder for illuminatingthe worl: at the point of welding at on intensityopproximately equal tothat produced by the welding arc during weldins, and means forming 2,part of said electrode holder for controlling said last mentioned means.

3. Arc welding apparatus comprising an electrode holder, means forsupplying welding current to on electrode supported in said holder,

means for illuminating the work at the point of welding at an intensityapproximately equal to that produced by the welding arc during welding,

and means responsive to the ignition of-the welding are forextinguishing said illuminating means and to-the extinction of said arefor igniting said illuminating means.

S BREDTSCHNEIDER.

